Hello there
if you read my signature line you will get the answer to your first question.Robin finished his radiotherapy on April 13th,and his recurrence happened in June.As he has had all the treatment options then his choices will likely be limited to chemo or more surgery.

If his recurrance was diagnosed by MRI or biopsy,or just plain visual examination,then it is unlikely to be a false positive ,which tend to relate more to PET scans.If it was infection then he would have all the symptoms of generalised in fection ie:Fever,chills,localised heat and redness,and with an offensive odour.If the size of the swelling alters over 24 hours it will be fluid accumulating round the swelliing when he is upright,and diffusing when he lays down.Fluid will be soft and mobile,tumour in the parotid gland will be hard and fixed.You don't say how old he is as this too can have an effect on recovery,although our elder statesman here on OCF has had more surgeries than Frankenstein had and he is still bouncing around .
Its a lottery my dear with big winners and losers,there seems no logic or rhyme and reason to who wins and more so who loses,and one things for certain,there are no guarentees.

liz